基于比较代谢组学的理性优化方法提高阿维菌素产量

Enhanced avermectin production by rational feeding strategies based on comparative metabolomics

摘要:

[目的]利用比较代谢组学的分析方法，研究不同发酵培养基中阿维链霉菌的胞内代谢差异，揭示合成阿维菌素的关键代谢物和代谢途径，再通过理性优化添加主要关键代谢物，提高阿维菌素产量。[方法]对M1和M2培养基中生长的菌体进行基于GC-MS的胞内代谢组学分析，通过理性添加强化前体代谢物，确定阿维菌素高产培养基。[结果]GC-MS共检测到232种物质，能够精确匹配70种胞内代谢物，通过PCA和PLS分析，最终确定了21种已知的胞内代谢物与阿维菌素的生物合成密切相关。其中乳酸、丙酮酸、琥珀酸、苏氨酸、异亮氨酸、缬氨酸和油脂类物质对阿维菌素的产量影响较为显著。通过单独或组合优化添加这些前体，阿维菌素的产量从5.36 g/L提高到了5.92 g/L，增加了10.4%。[结论]基于比较代谢组学分析的理性优化培养基的方法可有效提高阿维菌素的产量，并为提高当下生物基产品的产量提供了新思路。

Abstract:

[Objective] In order to reveal key metabolites and metabolic pathways of avermectin, comparative metabolomics approach was used to analyze the difference of key intracellular metabolites of Streptomyces avermitilis in different fermentation media. Then the rational feeding approach was used to enhance avermectin production.[Methods] Mycelial samples in M1 and M2 media were analyzed by GC-MS based comparative intracellular metabolomics. Based on the deficiency of relative metabolic pathways, single precursor supplement and combined precursors supplement were exerted, and the optimized medium M3 was obtained to enhance avermectin production.[Results] In total 232 intracellular metabolites were identified and 70 of them were accurately matched, and 21 metabolites influencing avermectin biosynthesis were finally verified by PCA and PLS analyses. Among them, lactic acid, pyruvic acid, succinic acid, threonine, isoleucine, valine and lipids determined the avermectin titer more obviously. When supplying with these precursors together to M2 at different time points, the titer increased by 10.4% from 5.36 g/L to 5.92 g/L.[Conclusion] The production of avermectin increased apparently with the help of comparative metabolomics analysis and rational feeding optimization. It also provides a new approach to enhance the yield of bioproducts.